It depends on how you are going to use it; what you mean by best. I'm not sure there is a consensus for a method that is best in every aspect always.

The problem can be divided into two parts: Searching and matching. Your question sounds focused on the search so here comes two examples of recent papers comparing different search methods:

This paper reviews different search methods using SAD for matching:

Review of energy efficient block-matching motion estimation algorithms for wireless video sensor networks (2012)

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6222702

This paper also compares different search methods:

A Novel Prediction-Based Directional Asymmetric Search Algorithm

for Fast Block-Matching Motion Estimation (2009)

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4801638

Try semi global block matching.. Better than bm